Jim 1/30 pools per minute
Sue 1/45 pools/min
Tony 1/90 pools/ min
Total = 3/90 + 2/90 + 1/90 = 6/90 = 1/15 pools/min
(1/15) pools /min * t = 1 pool
t = 15 min
Jim can fill a pool carrying buckets of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together?
A. 12 minutes
B. 15 minutes
C. 21 minutes
D. 23 minutes
E. 28 minutes
2 answers
Tony fills 1/6 in a quarter hour, not 1/4
1/2 + 1/3 +1/6 = 1 pool
1/2 + 1/3 +1/6 = 1 pool